This is a continuing program encompassing a number of basic problems related to ovulation and gamete transport particularly in the female reproductive tract: The areas of emphasis are: 1. Comparative studies on the ultrastructural and scanning electron microscopic characteristics of cilia during various times of the reproductive cycle. 2. Comparative studies of the ciliary activity as measured by a newly developed ciliary sensing device that records the rate of ciliary beat directly and instantaneously. This includes studies of the effects of various hormones and pharmacologic agents on ciliary beat. As in certain invertebrates we are attempting to determine whether or not the direction of ciliary beat can be reversed. 3. We are evaluating the function of the utero-tubal junction in controlling sperm transport into the oviduct. 4. We are proceeding to characterize sperm membrane changes during capacitation and the acrosome reactions prior to sperm penetration and fertilization by freeze-etching and labeling by various immunologic techniques.